The present invention relates to printed circuit board handling and manufacturing processes and, more particularly, to an improved printed circuit board support, printed circuit board conveying system, and printed circuit board processing system.
Conventional printed circuit board processing systems, e.g., SMT (surface mount technology) manufacturing systems, typically utilize a conveyor system to move a printed circuit board from station to station within the system. Often, the printed circuit board is supported or held in a manner that is insufficient to prevent the board from warping, twisting, or bending during processing. Accordingly, there is a need in the art of printed circuit board handling and processing for an improved printed circuit board support.
This need is met by the present invention wherein an improved printed circuit board support, an improved printed circuit board conveying system, and an improved printed circuit board processing system are provided. In accordance with one embodiment of the present invention, a printed circuit board support is provided comprising a support base, a spacer, and a spacer securement. The support base defines a support surface. The spacer engages the support surface. The spacer securement includes a projection and a recess. The projection adjoins one of the support base and the spacer. The recess is formed in the other of the support base and the spacer. The projection extends into the recess and the projection and the recess are configured such that the extension of the projection into the recess limits movement of the spacer relative to a plane parallel to the support surface.
The printed circuit board support may comprise two or more spacer securements. The projection may comprise a substantially cylindrical pin and the recess may comprise a cylindrical recess having a diameter slightly larger than the pin. The spacer may define an upper spacer surface spaced from and substantially parallel to the support surface.
In accordance with another embodiment of the present invention, a printed circuit board support assembly is provided comprising a support base and a plurality of spacers. The support base defines a support surface and at least one recess formed therein. The recess defines an opening on the support surface. The plurality of spacers define respective upper spacer surfaces and opposite spacer surfaces. The spacers define a range of respective thickness dimensions between respective ones of the spacer surfaces and corresponding ones of the opposite spacer surfaces. Each of the spacers includes at least one projection extending from the opposite spacer surface. The respective projections and the recess formed in the support base are sized to enable extension of the respective projections into the recess and to limit movement of the spacer relative to a plane parallel to the support surface.
In accordance with yet another embodiment of the present invention, a printed circuit board support is provided comprising a support base. The support base defines a support surface, a leading edge, a trailing edge, and a pair of lateral edges. The support base also defines a cut-out formed therein. The cut-out is positioned between the pair of lateral edges and extends from the leading edge in the direction of the trailing edge to a position between the leading edge and the trailing edge.
The leading edge, the trailing edge, and the pair of lateral edges may be defined in a substantially planar surface of the support base. The cut-out may be formed in the support surface of the support base. The printed circuit board support may further comprise a spacer and a spacer securement. The spacer engaging the support surface and including an additional cut out formed therein and the spacer securement arranged to secure the spacer to the support surface with the additional cut-out aligned with the cut-out formed in the support base. The additional cut-out and the cut-out in the support base may be coextensive. The additional cut out may be formed in an upper spacer surface of the spacer.
In accordance with yet another embodiment of the present invention, a printed circuit board support is provided comprising a support base defining a support surface. A base extension assembly is secured to the support base and is arranged to define a variable extension assembly height dimension and at least a portion of a height dimension of the printed circuit board support, wherein variation of the variable extension assembly height dimension results in variation of the height dimension of the printed circuit board support.
The base extension assembly may be further arranged such that the extension assembly height dimension varies in response to a force applied to the support surface. The base extension assembly comprises a spring-loaded extension including a spring arranged to compress in response to a force applied to the support surface. The base extension assembly may comprise a viscously damped extension arranged to compress in response to a force applied to the support surface. The base extension assembly may comprise a pair of support legs. Each of the pair of support legs may be arranged such that the extension assembly height dimension varies in response to a force applied to the support surface.
In accordance with yet another embodiment of the present invention, a printed circuit board support is provided comprising a support base, a base extension, and a magnetic source. The support base defines a support surface and a lower surface. The base extension is secured to the support base and is arranged to define at least a portion of a height dimension of the printed circuit board support. A magnetic source is secured to the base extension and is positioned such that the lower surface of the support base is arranged to secure the printed circuit board support to an object under magnetic force. The magnetic source may comprise a permanent magnet and may be secured within a cavity formed in the lower surface of the support base.
In accordance with yet another embodiment of the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails and a printed circuit board support. The pair of conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board and are configured to convey the printed circuit board along a conveyor path. The printed circuit board support is positioned to support a portion of the printed circuit board between the lateral edge portions. The printed circuit board support comprises a support base defining a support surface, a spacer engaging the support surface, and a spacer securement including a projection and a recess. The projection adjoins one of the support base and the spacer. The recess is formed in the other of the support base and the spacer. The projection extends into the recess. The projection and the recess are configured such that the extension of the projection into the recess limits movement of the spacer relative to a plane parallel to the support surface. A thickness dimension of the spacer is selected to enable engagement of the spacer with the printed circuit board.
In accordance with yet another embodiment of the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails, a printed circuit board support, and a stop mechanism. The pair of conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board and are configured to convey the printed circuit board along a conveyor path. The printed circuit board support is positioned to support a portion of the printed circuit board between the lateral edge portions and comprises a support base. The support base defines a support surface, a leading edge, a trailing edge, a pair of lateral edges, and a cut-out formed therein. The cut-out is positioned between the pair of lateral edges and extends from the leading edge in the direction of the trailing edge to a position between the leading edge and the trailing edge. The stop mechanism is positioned to engage the printed circuit board support at a point within the cut-out. The stop mechanism may include an actuator and a pin and may be configured to selectively extend and retract the pin to and from a position engaging the printed circuit board support at the point within the cut-out.
In accordance with yet another embodiment of the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails and a printed circuit board support. The pair of conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board and configured to convey the printed circuit board along a conveyor path. The printed circuit board support is positioned to support a portion of the printed circuit board between the lateral edge portions and comprises a support base and a base extension assembly. The support base defines a support surface. The base extension assembly is secured to the support base and is arranged to define a variable extension assembly height dimension and at least a portion of a height dimension of the printed circuit board support. Variation of the variable extension assembly height dimension results in variation of the height dimension of the printed circuit board support. The base extension assembly is configured such that the height dimension of the printed circuit board support permits engagement of the support surface with the printed circuit board.
In accordance with yet another embodiment of the present invention, a printed circuit board conveying system is provided comprising a pair of conveyor rails, a conveyor platform, and a printed circuit board support. The pair of conveyor rails are positioned to engage opposite lateral edge portions of a printed circuit board and are configured to convey the printed circuit board along a conveyor path. The printed circuit board support is positioned to support a portion of the printed circuit board between the lateral edge portions. The printed circuit board support comprises a magnetic source secured to the base extension assembly and positioned such that the lower surface of the support base secures the printed circuit board support to the conveyor platform under magnetic force, wherein the base extension assembly is configured such that the height dimension of the printed circuit board support permits engagement of the support surface with the printed circuit board.
In accordance with yet another embodiment of the present invention, a printed circuit board processing system is provided. The system includes a printed circuit board conveying system coupling a printed circuit board loader to a stencil printer, a pick and place machine, and a reflow oven. The printed circuit board conveying system comprises a pair of conveyor rails and a printed circuit board support according to the present invention.
In accordance with yet another embodiment of the present invention, a method of conveying a printed circuit board in a printed circuit board conveying system is provided. The conveying system is provided in accordance with the present invention and the conveying method comprises the steps of selecting one of the plurality of spacers as a function of its thickness and a thickness profile of the printed circuit board engaged by the pair of conveyor rails; installing the selected spacer by extending at least one of the respective projections into the recess; and engaging an upper spacer surface of the selected spacer with the printed circuit board.
In accordance with yet another embodiment of the present invention, a method of conveying a printed circuit board in a printed circuit board conveying system is provided. The conveying system is provided in accordance with the present invention and the conveying method comprises the steps of engaging the support surface of the support base with the printed circuit board engaged by the pair of conveyor rails and varying the height dimension of the base extension assembly as a function of a thickness profile of the printed circuit board.
In accordance with yet another embodiment of the present invention, a method of processing a printed circuit board in a processing system including a printed circuit board conveying system coupling a printed circuit board loader to a stencil printer, a pick and place machine, and a reflow oven is provided. The printed circuit board conveying system is provided in accordance with the present invention and the processing method comprises the steps of selecting one of the plurality of spacers as a function of its thickness and a thickness profile of the printed circuit board engaged by the pair of conveyor rails, installing the selected spacer by extending at least one of the respective projections into the recess, and engaging an upper spacer surface of the selected spacer with the printed circuit board within the operating envelope of the pick and place machine.
In accordance with yet another embodiment of the present invention, a method of processing a printed circuit board in a processing system including a printed circuit board conveying system coupling a printed circuit board loader to a stencil printer, a pick and place machine, and a reflow oven is provided. The printed circuit board conveying system is provided in accordance with the present invention and the processing method comprises the steps of engaging the support surface of the support base with the printed circuit board engaged by the pair of conveyor rails within the operating envelope of the pick and place machine and varying the height dimension of the base extension assembly as a function of a thickness profile of the printed circuit board.
Accordingly, it is an object of the present invention to provide an improved printed circuit board support, an improved printed circuit board conveying system, and an improved printed circuit board processing system. Other objects of the present invention will be apparent in light of the description of the invention embodied herein.